What Is the Purpose of the AV Nodal Delay

Multiple Choice

What is the purpose of the AV nodal delay

A) to ensure that all blood from the atria flows into the ventricles prior to ventricular systole
B) to ensure that all blood from the ventricles flows into the atria prior to atrial systole
C) to ensure that tetanic contraction of cardiac muscle is not possible
D) to ensure that heart rate slows down by parasympathetic stimulation